Planet Earth Weekly

Climate Change and Renewable Energy: Saving Our Planet for Future Generations

The Demographic Transition

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The Population Growth Cycle

With global warming rapidly taking place, can we feed the world’s growing population? (Photo credit: mattlemmon)

By John J. Hidore

While the population is growing in most countries, it is in these less developed countries that the greatest growth on the planet is taking place.With the effects of global warming, feeding the earth’s population will be a future challenge!

November 22, 2013–In the year 2013 the global population is growing at about a quarter million each day. This is a recent trend as through most of human history the population grew very slowly. Humans began as hunters and gatherers and evolved through farmers and herders to the consumer culture of the 21st century. Through this process, life style population growth rates changed following a widely accepted model known as the demographic transition. The model of this shift shows a change from high birth and death rates to low birth and death rates. The model of the demographic transition is based upon events in Europe and involves several stages.

Hunters and Gatherers
In the first stage, humans were hunters and gatherers–until fairly recently on the earth’s timeline. Their food supply was subject to the whims of weather and other elements. Birth rates and death rates were high and varied widely. The annual rate of growth was close to zero. However, as new tools were created that increased the food supply, the population grew slowly, but at an increasing rate. About 10,000 years ago humans changed from being hunters and gatherers to farmers and herders. Once the agricultural revolution got underway, the rate of technological development began to increase steadily. Agriculture gave people control over their food supply, as did the domestication of animals. The increasing technology greatly increased the food supply and consequently the growth rate. Around 1650 the human population reached the 500 million mark.

The Industrial Revolution And Population Growth
The second stage of the demographic transition began with the onset of the industrial revolution. The Industrial Revolution began in what is now Britain, in the period from 1783 to 1812. The industrial revolution resulted in significantly lengthening the average life span, increasing the rate of population growth. The impact of the industrial revolution on the global population was phenomenal! It had taken hundreds of thousands of years for the population to reach 500 million. It took less than 200 years to add the next 500 million.

During this second stage, death rates fell rapidly due to better food and advances in medicine and public health. In much of Western Europe, the death rate dropped sharply, but the birth rate stayed high. This greatly increased the rate of growth from approximately 0.1 percent per year in 1750 to about 1.4 percent by the third quarter of the 1800’s. The growth rate in these countries exploded and the rate of population growth increased rapidly, greatly increasing the earth’s total population. The growth rate in European countries and their colonies was far greater than in the rest of the world at this time.

Increasing Life Span
The third stage of growth occurred when the birth rate dropped, while the death rate continued to decline, but slower than before. By the last quarter of the 1800’s, the birth rate in Europe began to decline, thus slowing the growth rate. The exact reasons for the drop in the birth rate is not known. In this third stage, the birth and death rates were low, with the birth rate only slightly higher than the death rate. Once again, the difference between the birth and death rate was small, both at much lower levels than in the first stage. The drop in death rates resulted in the average human life-span increasing from about 30 to more than 70 years. Each country went through the demographic transition at a different time and rate. By 1930 the industrialized countries of Europe had passed through the transition and reached the final stage of low growth rates. Those countries which have joined the industrial nations since 1930 have also gone through the demographic transition. Since 1900, growth rates in the industrialized countries have averaged between 0.25 and l.0 percent. The stages merge from one to the next,  but do not take place everywhere at the same time.
Population Growth Rate of Undeveloped Countries
Most of the nearly 200 nations existing today have not reached the third phase. Many less developed countries have not changed to an industry based economy. These countries are largely still agricultural. They have remained in the second stage, which is one of high birth rates and declining death rates. Where basic health improvement measures have been put in place, the death rate has dropped substantially. The large gap means a high growth rate. The global average growth rate in 2011 was some 1.2%. The CIA Fact book estimates the growth rate in Zimbabwe at 4.38% and that of Libya at 4.85%. This is in comparison to the United Kingdom at 0.55% and the United States at 0.9% While the population is growing in most countries, it is in these less developed countries that the greatest growth on the planet is taking place.

The highest growth rates are occurring in nations that are already in danger of becoming failed states. In many of these nations the ruling elite have little desire to support family planning, making the economic and social problems worse. Birth rates could drop substantially and rapidly, stabilizing the global population at 0%, but this seems highly unlikely in the near future. With the effects of global warming, feeding the earth’s population will be a future challenge!

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Author: Planet Earth Weekly

My goal, as a responsible adult, is to leave a planet that people, plants, and animals can continue to occupy comfortably. I am an educator by profession. While educating myself on Climate Change and Renewable Resources, I hope to share my knowledge and images with those that share my concern. Dr. John J. Hidore is a retired professor from the University of North Carolina at Greensboro and I am proud to call him my Uncle. His work has taken him to regions across the globe—including the Middle East, where he conducted research for a year in the Sudan. He has written many books, such as Climatology: An Atmospheric Science and Global Environmental Change.----Linn Smith

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